MRI Transfer Station and Dock

ABSTRACT

A patient table adapted for use in association with an MR scanner for neonatal infants is provided. The patient table has an extendable patient bed attached to and extendable from the patient table. The patient bed may be at least partially inserted into an MR scanner without requiring the patient table to enter the MR scanner. A transport mechanism is on the underside of the patient table so that it may be readily moved over the floor on which it rests. The patient table includes a latching mechanism that may operate to releasably attach the patient table to a patient table docking assembly. The docking assembly is operative to selectively move the patient table towards, into and away from the MR scanner.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority benefit of U.S. ProvisionalPatent Application Ser. No. 61/693,937 filed Feb. 2, 2012 and is furtherrelated to U.S. Provisional Patent Application Ser. No. 61/429,612 alsofiled Jan. 4, 2011.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to magnetic resonance imagingequipment suitable for use in neonatal care, and, more particularly, toan MRI transfer station and dock for receiving an infant from anincubator and to assist with preparing the infant for an MR scan.

BACKGROUND OF THE DISCLOSURE

Today premature infants weighing less than 1 kg may be stabilized andallowed to develop in neonatal intensive care units (NICUs). Magneticresonance imaging (MRI) is a powerful technique for diagnostic purposesbut is not routinely performed on these infants due to a number oftechnical and logistical challenges.

When a mother has a high-risk pregnancy, it is possible that the babycould be born prematurely and would require treatment in a neonatalintensive care unit or NICU. Also, unexpected early delivery may requirethat an infant be treated in an NICU.

One difficulty in utilizing MRI for these premature infants ismonitoring the vital signs and life support of the infant during MRexamination. Parameters that must be monitored during examinationinclude electrolyte levels, hydration and temperature. A seconddifficulty in utilizing MRI is that the infant must be moved from anincubator or isolette into and out of the MR scanner. This movementplaces the infant at risk for injury.

Despite challenges, MRI has the potential to play an importantdiagnostic role in the care and management of neonates. The full use ofthis imaging technique requires that the imaging take place as early asthe first few hours of life. At this stage, however, the infants arehemodynamically unstable. Accordingly, transporting and maintaininghomeostasis in these fragile infants presents difficulty.

Another challenge in using MRI for neonates is that MRI systems arefrequently located in Radiology departments outside of and perhapsdistant from the NICU. Consequently, the neonate must be escorted out ofthe NICU. This may present certain logistical and technical challengeswith respect to controlling the neonate's environment. Furthermore,removing staff from the NICU to transfer and attend to one baby outsidethe NICU can place the remaining babies in the NICU at increased risk ofa reduced level of care due to decreased staff coverage.

An MR compatible transport incubator and imaging system has beendeveloped (Dumoulin et. al.) and is currently in use. Concepts inMagnetic Resonance (Magnetic Resonance Engineering), Vol. 15(2) 117-128(2002). This system is a self-contained MR compatible transportincubator which carries the infant from the NICU to an MR scannerlocated in or near the NICU. With this approach the baby must first betransferred from its “home” incubator or isolette in the NICU into thetransport incubator. The transport incubator is then moved to the MRscanner where it is docked with the scanner. A portion of the transportincubator containing the baby is then moved into the center of the MRimaging system magnet where MR imaging is performed. While this approachhas the advantage of not disturbing the baby while it is in thetransport incubator, even during MR scanning, it has several limitationsincluding: a) infants must be fully detached from the monitoringequipment in their home incubator to be transferred into the transportincubator, b) the MR system that is used for imaging must have a borelarge enough to accommodate the portion of the transport incubatorcontaining the baby (thereby requiring a large heavy magnet), c) thebaby and its attending staff need to leave the NICU for scanning, and d)because the transport incubator must be fully MR compatible whileproviding full life support for the baby, the system is heavy andexpensive.

An alternate approach to provide MR imaging to newborn babies has beendisclosed by Feenan in U.S. Pat. No. 7,599,728. In this approach arelatively smaller MR magnet is employed and MR-compatible incubatorsare docked to the magnet thereby permitting the baby to be slid into themagnet for imaging. While this approach has the benefit of providing amagnet that is more easily installed in the NICU, it does have severallimitations including the need for MR compatible incubators to be usedthroughout the NICU, or the transfer of a neonate from anon-MR-compatible home incubator to an MR-compatible incubator. Thisapproach also limits the access to the attending staff as they preparethe infant for MR scanning. In particular, the staff must reach throughthe incubator to push the baby into and out of the magnet.

SUMMARY

A patient table adapted for use in association with an MR scanner forneonatal infants is disclosed. The patient table may include anextendable and movable patient bed attached to a top surface of thepatient table. The patient bed may include an extending mechanism that,when extended, causes the patient bed to be extended and at leastpartially project from the patient table. The patient bed may bedimensionally constructed such that it may be at least partiallyinserted into an MR scanner without requiring the patient table to enterthe MR scanner. A transport mechanism, such as a set of wheels, may beattached to the underside of the patient table so that it may be readilymoved over the floor on which the patient table rests. The patient tablealso includes a latching mechanism that may operate to releasably attachthe patient table to a patient table docking assembly. The dockingassembly may be operative to selectively move the patient table towardsand away from the MR scanner.

The present disclosure will now be described in more detail withreference to exemplary embodiments thereof as shown in the accompanyingdrawings. While the present disclosure is described below with referenceto exemplary embodiments, it should be understood that the presentdisclosure is not limited thereto. Those of ordinary skill in the arthaving access to the teachings herein will recognize additionalimplementations, modifications, and embodiments, as well as other fieldsof use, which are within the scope of the present disclosure asdescribed herein, and with respect to which the present disclosure maybe of significant utility.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to facilitate a fuller understanding of the present disclosure,reference is now made to the accompanying drawings, in which likeelements are referenced with like numerals. These drawings should not beconstrued as limiting the present disclosure, but are intended to beexemplary only.

FIG. 1 a is a perspective view showing an exemplary MR imaging system,an exemplary docking mechanism, and an exemplary patient tablecontaining a neonate in accordance with the present disclosure;

FIG. 1 b is a perspective view showing the attachment of the patienttable to a docking mechanism to prepare the neonate for movement inaccordance with the present disclosure;

FIG. 1 c is a perspective view showing the extension of the neonate onthe MRI transfer station towards the magnet in the MR scanner;

FIG. 1 d is a perspective view showing a further extension of theneonate on the MRI transfer station towards the magnet in the MRscanner;

FIG. 1 e is a perspective view that shows the movement of the neonateinto the exemplary MR imaging system caused by motion of the dockingmechanism that motion brings the patient table closer to the magnet andbrings the neonate into the chamber of the MR scanner for imaging;

FIG. 2 is a perspective view of one embodiment of an MRI transferstation suitable for preparing a neonate for MR imaging;

FIG. 3 is a top plan view of an exemplary MR magnet with barrier polesto limit access to the magnet; and

FIG. 4 is a top plan view of an exemplary MR magnet with an elevatedfloor barrier to limit access to the magnet.

DETAILED DESCRIPTION

The use of MRI techniques for infants, and in particular neonates, ishighly desirable. MRI techniques provide diagnostic information withoutpatient exposure to ionizing radiation, and are suitable for extendedand repeated studies.

MR techniques provide excellent anatomic visualization and functionalinformation. They can be used to measure neural fiber track developmentand have a number of potential clinical uses including, but not limited,to diagnosis of brain trauma, cardiac abnormalities, congenital defectsand the assessment of lung development.

There are, however, a number of challenges in the use of MRI forneonatal imaging. Patient access during scanning can be difficult as MRmagnets are typically large and surround the patient. Safety concernsinclude forces on ferromagnetic objects, potential for rf heating andacoustic noise. Also, logistics may be difficult, as MR scanners tend tobe in radiology departments, while neonate infants are typically in theNICU.

FIGS. 1 a-1 d depict an exemplary MRI and incubator system 100 in or forwhich the techniques for the MR imaging of neonates in accordance withthe present disclosure may be implemented. The illustrated MRI systemcomprises an MRI scanner 102. Since the components and operation of theMRI scanner are well-known in the art, only some basic componentshelpful in the understanding of the system 100 and its operation will bedescribed herein.

The MRI scanner 102 may comprise a cylindrical superconducting magnet104, which generates a static magnetic field within a bore 105 of thesuperconducting magnet 104. The superconducting magnet 104 generates asubstantially homogeneous magnetic field within the magnet bore 105. Thesuperconducting magnet 104 may be enclosed in a magnet housing 106.

A set of cylindrical magnetic field gradient coils 112 may also beprovided within the magnet bore 105. The gradient coils 112 can generatemagnetic field gradients of predetermined magnitudes, at predeterminedtimes, and in three mutually orthogonal directions within the magnetbore 105. With the field gradients, different spatial locations can beassociated with different precession frequencies, thereby giving an MRimage its spatial resolution. An RF transmitter coil 114 is positionedwithin the gradient coils 112. The RF transmitter coil 114 emits RFenergy in the form of a magnetic field for the purpose of exciting MRsignals during image acquisition. The RF transmitter coil 114 can alsoreceive MR response signals. The MR response signals are amplified,conditioned and digitized into raw data as is known by those of ordinaryskill in the art.

The present disclosure provides an apparatus and a technique for safelyand effectively transferring an infant from the primary care area to theMR magnet. In one particular embodiment, the present disclosure providesthe means to transfer a neonate from the NICU to an MR magnet locatedeither in a radiology department or in the NICU itself. The presentdisclosure accomplishes this by providing an MR-compatible transferstation that can be attached to the MR magnet. This station creates anMR compatible environment that, if desired the baby can be moved intowithout being detached from patient monitoring or life support systems.Once stabilized on the transfer station, the baby can then be moved intothe magnet for imaging. Note that the in the present disclosure anincubator does not need to be fully MR compatible and can be constructedwith some MR incompatible elements such as electrical motors.

Referring again to FIGS. 1 a-1 e, a patient table 130 containing aneonate 110 is shown. Neonate 110 may be placed on a movable patient bed120 attached to the top of patient table 130. Movable patient bed 120may be disposed on and may roll on a track 125. In alternate embodimentsof the present disclosure the function of track 125 can be performedwith alternate designs incorporating slides, cables, pulleys or thelike. The patient table 130 may have wheels and may be designed to rollon the floor, so that the neonate can be placed on the patient table ina location remote from MRI scanner 102, such as near an incubator.Patient table 130 also have a latching mechanism 124 that may permit thepatient table 130 to be temporarily and releasably attached to a dockingassembly 140.

Docking assembly 140 may include a hitch mechanism 150 that may beattached to a moving tractor assembly 160. Moving tractor assembly 160may be attached to a belt 170 which may be moved by a dock motor 180.Turns of the motor shaft may result in belt motion which in turn maycause the moving tractor assembly 160 to move relative to the fixedportion of docking assembly 140. In alternate embodiments of the presentdisclosure, the function of belt 170 may be accomplished with anysuitable drive device as known in the art including but not limited to ascrew drive, a chain drive, or a gear assembly.

FIG. 1 b shows the docking of the patient table 130 to docking assembly140. In the current embodiment of the disclosure latching mechanism 124may engage hitch mechanism 150 and the two may then become coupled.Decoupling of latching mechanism 124 and hitch mechanism 150 can beperformed manually or automatically by the system when removal ofpatient table 130 from the vicinity of MRI scanner 102 is desired.

FIG. 1 c shows the extension of the neonate 110 and movable patient bed120 towards MRI scanner 102. In the current embodiment of the presentdisclosure, neonate 110 may be prepared for MR scanning while in thisgeneral location. Preparations may include safety checks, swaddling,attachment of additional monitoring equipment, placement of MR receivecoils, and/or attachment of hearing protection to the neonate 110.

FIG. 1 d shows the further extension of the neonate 110 and movingpatient bed 120 into the MRI scanner 102. Note that during thisextension the neonate is not moved with respect to movable patient bed120.

FIG. 1 e shows the insertion of the neonate 110 and moving patient bed120 into the MRI scanner 102. Note that during this insertion theneonate is not moved with respect to movable patient bed 120, but may beplaced in the imaging volume of MRI scanner 102.

FIG. 2 shows one embodiment of the movable patient bed 120 in greaterdetail. Moving patient bed 120 may include a bed surface 122 and cover220. The cover 220 may incorporate one or more cover locking pins 230that are designed for insertion into a like number of correspondingcover pin sockets 240. The cover locking mechanism shown here isexemplary. It should be understood that alternate mechanisms forattaching the cover 220 to the moving patient bed 120, including but notlimited to hinges, slots, clamps and slides. If desired, neonate accessports similar to those found in conventional neonate incubators can beincorporated into the cover 220. It should be obvious to one skilled inthe art that patient table 130 and all subassemblies exposed to strongmagnetic fields may be constructed using MR compatible materials.

The present disclosure is particularly advantageous in that it minimizesthe transfer time from the NICU to MRI scanner 102 and provides lessstress on the infant. Another advantage of the present disclosure isthat babies do not need to be fully detached from patient monitoringequipment which can be integrated as desired into patient table 130.This further reduces preparation times and stress on the infant. Oncethe baby is stabilized, the baby and the patient table 130 can beinserted into the magnet to place the neonate 110 in the imaging regionof the MRI scanner. This can be done manually by further extendingmoving patient bed 120 or under system control with appropriate drivingof dock motor 180 to move patient table 130. This approach ensures thatthe local environment of the neonate 110 is not altered as it is broughtinto the center of the imaging system. Furthermore, because a transportincubator is not required to be fully inserted in the magnet, the MRmagnet can be small and lightweight. This makes it more easily installedwithin the confines of the NICU, and provides improved access to MR forpremature babies. In addition, the present disclosure permits MRscanning to be performed with fewer support personnel, and/or placessupport personnel closer to the other babies present in the NICU. Withthe present disclosure MR imaging can be made available to all babies ina NICU (typically between 10 and 60) using a single MR magnet and asingle patient table that may be used for each compatible incubator inthe NICU.

In particular, the present disclosure relates to a transfer station forpreparing an infant, including neonates, prior to transfer into themagnet for imaging. The transfer station may have all of thefunctionality of the neonate's home incubator, but implemented in anMR-compatible and MR-safe manner.

Once the infant is on movable patient bed 120, the infant can beprepared for MR scanning. As will be recognized by those skilled in theart of MR scanning, MR scanning frequently requires that several stepsbe performed before a patient can be inserted into an imaging magnet.These steps may include: a) immobilization of the patient (in the caseof neonatal imaging, swaddling is frequently sufficient), b) theoptional insertion of IV tubes for contrast injections, c) theattachment of MR imaging coils, d) a safety check to verify that noferromagnetic objects are present, e) placement of hearing protection,and f) verification of patient stability and comfort. All of these stepsneed to be performed while the patient is near the magnet, and requireaccess to the patient which is not possible with most incubator designs.

Another aspect of the moving patient bed 120 of the present disclosureis that it can provide full environmental control for the neonate whenused with cover 220. Many neonates are too young to be able to fullycontrol their internal temperature, and it is well known to thoseskilled in the art that small neonates must be kept warm. In the presentdisclosure, this can be done with warm air and/or a radiant heaterdriven by a temperature controller. In one embodiment of the disclosure,a thermocouple or similar temperature sensor modified for use in the MRenvironment with non-ferromagnetic parts and appropriate rf filteringmay be used to provide feedback to the temperature controller to providesuitable temperature control. In another embodiment of the presentdisclosure a physiologic monitoring system may be utilized. This systemmay be MR compatible and MR safe. It can be used if desired in place ofthe patient monitoring systems found in the neonate's home incubator.

As shown in FIG. 3, a safety barrier constructed with in-room barrierssuch as poles 350 in the floor may be used and may be spaced to preventincubators or other devices from getting within a predetermined fringemagnetic field strength 360 (typically chosen to be 5 Gauss) at aselected distance 370 of the magnet. With such an approach the patienttable 130 can be placed into a safe position 340 from which the neonate110 is moved and prepared for MR scanning. With an incubator in safeposition 340 the neonate 110 may be moved towards MR scanner 102 alongan axial route 380. Alternatively, the incubator can be placed in analternate safe position such as 340 a and the neonate 110 may be movedto the transfer station 200 along an alternate route such as 380 a. Oncethe neonate is prepared for MR scanning, it can be moved together withthe patient table into the isocenter 320 of the MR scanner 102.

Alternatively, the barrier can be augmented with a step design as shownin FIG. 4 in which the floor that accommodates the NICU incubator islower than a raised floor 410 surrounding the magnet. The step createdby the two levels of the floor acts to prevent the incubator fromapproaching too close to the magnet.

The patient table 130 may in one embodiment, as shown in FIG. 1, be openlike an isolette. In one embodiment, the open isolette may be configuredwith radiant heating. In another embodiment, the transfer station may beenclosed like an incubator with the addition of a cover. In oneembodiment, the enclosed transfer station may be configured to providewarm circulating air.

As mentioned, in one embodiment, patient table 130 may be equipped toinclude all necessary life support and monitoring equipment. Suchequipment includes, but is not limited to, EKG monitoring, IV tubes,oxygen monitors, ventilators, breathing gases, and bilirubin treatment.If needed, patient table 130 can be powered by an external supply or anon-board MR-compatible battery. Alternatively, the patient table 130 maybe manually advanced or extended as desired.

In one embodiment of the disclosure, patient table 130 may includephysical barriers to prevent extraneous objects being sucked into theinfant when the infant is inside the magnet. In one embodiment, thebarrier may include a substantially full enclosure made of clearengineering plastic that is resistant to impact damage. This arrangementmay provide full visual access of the baby but may provide a barrier tothe entry of other objects into the magnet.

In one embodiment, a Faraday cage may be built into patient table 130 toprevent RF interference from degrading the MR image. This would beparticularly advantageous if the MR system is not placed in an RF screenroom. Should a Faraday cage be incorporated into the transfer station,an internal rf tight panel or door may be added between the magnet andthe transfer station. It may also be desirable to provide penetrationfilters for monitoring leads to minimize rf interference during MRimaging.

In an even further embodiment, the transfer station may incorporate ascale for weighing the infants.

While the foregoing description includes many details and specificities,it is to be understood that these have been included for purposes ofexplanation only, and are not to be interpreted as limitations of thepresent disclosure. It will be apparent to those skilled in the art thatother modifications to the embodiments described above can be madewithout departing from the spirit and scope of the disclosure.Accordingly, such modifications are considered within the scope of thedisclosure as intended to be encompassed by the following claims andtheir legal equivalents.

1. A patient table adapted for use in association with an MR scanner forneonatal infants, said patient table comprising: A patient table base;an extendable and movable, MR-compatible patient bed attached to a topsurface of said patient table base, said patient bed comprising anextending mechanism that when extended causes said patient bed to beextended and at least partially project from said patient table base,said patient bed being dimensionally constructed such that it may be atleast partially inserted into an MR scanner bore without requiring saidpatient table to enter the MR scanner bore; a transport mechanismattached to an underside of said patient table adapted to permit thepatient table to be readily moved over the floor on which the patienttable rests; a coupling adapted to releasably attach said patient tableto a patient table docking assembly, said docking assembly beingoperative to selectively drive said patient table towards and away fromsaid MR scanner.
 2. The patient table as defined in claim 1, whereinsaid patient bed further comprises a cover releasably attached theretoin a manner so as to provide at least a partially enclosed space forcontaining a patient on the patient bed.
 3. The patient table as definedin claim 2, wherein said cover is attached to the patient bed by coveralignment pins.
 4. The patient table of claim 2, wherein said patienttable is equipped with life support and monitoring mechanisms.
 5. Thepatient table as defined in claim 1, wherein the patient table isconfigured as an open isolette.
 6. The patient table as defined in claim1, wherein said patient bed extending mechanism comprises one or morewheels disposed on the underside of the patient bed, said patient tablefurther including at least one track disposed on said patient table basethat receives and guides said one or more wheels such that the patientbed may roll on said at least one track so as to at least partiallyextend from said patient table base.
 7. The patient table as defined inclaim 6, wherein said transport mechanism comprises a plurality of tablebase wheels.
 8. The patient table as defined in claim 6, wherein saidpatient bed comprises two or more surfaces that are fastened together ina slidable arrangement with respect to each other so as to providefurther capabilities for the bed to extend from said patient table base.9. The patient table as defined in claim 1, further comprising a scalefor weighing the neonatal infant.
 10. A patient transfer station anddocking system suitable for use in association with an MR scanner forneonatal infants, said system comprising: a patient table comprising apatient table base and further comprising an extendable and movable,MR-compatible patient bed attached to a top surface of said patienttable base, said patient bed comprising an extending mechanism that whenextended causes said patient bed to be extended and at least partiallyproject from said patient table base, said patient bed beingdimensionally constructed such that it may be at least partiallyinserted into an MR scanner bore without requiring said patient table toenter the MR scanner bore, said patient table further comprising atransport mechanism attached to an underside of said patient tableadapted to permit the patient table to be readily moved over the flooron which the patient table rests; a transfer table docking assemblycomprising a hitch attached to a movable tractor, said movable tractorconfigured to be driven by a dock motor, said docking assembly hitchconfigured to selectively engage patient table so as to releasablycouple the docking assembly and the patient table together; wherein saiddock motor is selectively operative to move said patient table towardsand away from said MR scanner as desired.
 11. The system as defined inclaim 10, wherein said patient bed further comprises a cover releasablyattached thereto in a manner so as to provide at least a partiallyenclosed space for containing a patient on the patient bed.
 12. Thesystem as defined in claim 10, wherein said cover is attached to thepatient bed by cover alignment pins.
 13. The system of claim 10, whereinsaid patient table is equipped with life support and monitoringmechanisms.
 14. The system as defined in claim 10, wherein the patienttable is configured as an open isolette.
 15. The system as defined inclaim 10, wherein said patient bed extending mechanism comprises one ormore wheels disposed on the underside of the patient bed, said patienttable further including at least one track disposed on said patienttable base that receives and guides said one or more wheels such thatthe patient bed may roll on said at least one track so as to at leastpartially extend from said patient table base.
 16. The system as definedin claim 15, wherein said transport mechanism comprises a plurality oftable base wheels.
 17. The system as defined in claim 16, wherein saidpatient bed comprises two or more surfaces that are fastened together ina slidable arrangement with respect to each other so as to extend fromsaid patient table base in a telescoping manner.
 18. The system asdefined in claim 10, further comprising a manual release operative toselectively decouple the docking assembly and the patient table.
 19. Thesystem as defined in claim 10, wherein said movable tractor is driven bya drive belt.
 20. The system as defined in claim 10, wherein saidmovable tractor is driven by at least one of a screw drive, a gearassembly and a chain drive.
 21. A method of providing a neonatal infantwith an MR imaging scan, the method comprising the steps of: a)providing a patient table comprising a patient table base and furthercomprising an extendable and movable patient bed attached to a topsurface of said patient table base, said patient bed comprising anextending mechanism that when extended causes said patient bed to beextended and at least partially project from said patient table base,said patient bed being dimensionally constructed such that it may be atleast partially inserted into an MR scanner bore without requiring saidpatient table to enter the MR scanner bore, said patient table furthercomprising a transport mechanism attached to an underside of saidpatient table adapted to permit the patient table to be readily movedover the floor on which the patient table rests; b) providing a transfertable docking assembly comprising a hitch attached to a movable tractor,said movable tractor configured to be driven by a dock motor, saiddocking assembly hitch configured to selectively engage said patienttable so as to releasably couple the docking assembly and the patienttable together, said dock motor selectively operative to move saidpatient table towards and away from said MR scanner as desired; c)placing an infant on said extendable and movable patient bed; d)engaging said docking assembly hitch with said patient table so as toreleasably couple the docking assembly and the patient table together;e) operating said extending mechanism such that said patient bed atleast partially projects from said patient table base; f) preparing theinfant for MR scanning; g) positioning said infant within said MRscanner by operating said dock motor; and h) activating the MR scannerto obtain MR imaging of the infant.
 22. The method of claim 21, whereinsaid step of preparing the infant for MR scanning includes at least oneof: a) immobilizing the infant; b) inserting IV tubes into the infant;c) providing the infant with hearing protection; d) executing a safetycheck of the MR scanner and the infant to verify that no extraneousferromagnetic objects are present; and e) verifying the infant'sstability.